Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the read-only nature is covered. The description adds valuable specificity beyond annotations: 'No account access, no order placement or fund transfers' and 'Not investment advice.' This fills in the operational envelope without contradicting the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, dense sentence spread over a few lines. It front-loads the core purpose, then gives routing alternatives, then safety disclaimers. Every clause contributes meaning; there is no fluff or repetition. It is concise while packing substantial information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 8 optional parameters, an existing output schema, and comprehensive schema descriptions, the description covers the essential context: what the tool returns, how to adjust scope, which siblings cover adjacent use cases, and its safety boundaries. Nothing critical for an agent to correctly invoke the tool is missing, and the output format is already handled by the output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all eight parameters are already documented in the input schema. The description mentions 'scope=full adds apy_base_30d, ...' but this duplicates the schema's own description for scope. The main added value is the overall context that pools are sorted by APY or TVL, but that is not a parameter-specific explanation. The schema carries the semantic load, so a baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource: 'Lending and LP pools by APY or TVL.' This precisely states what the tool retrieves and immediately distinguishes it from sibling tools like get_platform_info and get_platform_history, which are explicitly referenced. The purpose is clear and unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit routing guidance: 'One protocol profile→get_platform_info. TVL series→get_platform_history.' It also frames the tool's context as read-only public research data, clarifying when it is appropriate to use. This is strong, actionable guidance for an agent deciding between tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.